In conventional page printers and copiers, sheets of paper or other sheet media are pulled from a stack and fed downstream into the print engine components where the desired image is formed on each sheet. The sheets of paper are typically stacked in a cassette, tray or similar type of paper holder. For ease of discussion purposes, the term "paper tray" or "tray" will be used herein in reference to all types of cassettes, trays, or other holders, regardless of orientation (i.e., horizontally or vertically disposed) and regardless of size or other variations. Paper trays may hold different types, sizes or color of paper or other flat media. Each tray may be a cassette assembly that includes paper feed components, such as a feed roller, shaft and gears, or the tray may simply be fitted in a housing for interconnection with a host image processing device. Most paper trays hold the sheet media stacked in a flat, horizontal orientation. Other trays are vertical in orientation, holding the media in an upright, on-end position, and may use side adjusters for guiding the paper into the holder and adaptively retaining the paper therein.
Certain paper trays employ angled, rounded or curved edges to help guide and slide the paper into its resting position within the tray as the paper is manually loaded therein by a user. Curved edges are notably used in vertically oriented paper trays. In vertical trays, the paper is inserted in a generally upright, on-end position into a mouth opening of the tray. The paper is dropped or pushed further into the tray until it reaches its resting or fully loaded position within the tray. An angled or curved edge may be implemented on the tray at the opening to widen the opening and to assist in guiding the paper into the tray. Optionally, as mentioned, side adjusters are configured on each side of the tray to help align the paper within the tray.
One problem associated with enlarged tray openings is that it is difficult for a user to know how much paper will actually fit in the tray because the opening is wider than the internal dimension of the tray. Thus, a user may attempt to load more paper into the tray than it is capable of physically handling. In such instances, the paper may become wedged too tightly within the tray and thereby cause a paper jam when the paper is automatically picked from the tray by the paper handling system for processing through the imaging device.
Accordingly, an object of the present invention is to inhibit overfilling of a paper tray that employs an enlarged mouth opening to thereby reduce paper jams.